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In this study the combination of ultrasound (USN) + membrane ultrafiltration (UF) was used to separate Spirulina saccharides (SPS). The results showed that USN significantly (p < 0.05) increased the average high-added-value compounds yield (mainly protein 572.8 mg/g, saccharides 133.6 mg/g and polyphenols 33.6 mg/g, dw) when the setting of 400 W/10 min was applied. Scanning electron microscope (SEM) results showed that USN treatment effectively destroyed Spirulina microstructure. The extraction efficiency differed according to USN total energy consumption, with higher extraction efficiency observed when a cooling system was not used. Different molecular weight cut-offs (MWCOs) membranes were used to separate SPS. Relative high purity SPS (∼70%) were obtained when 4 and 10 kDa membranes were used, while a higher separation efficiency occurred when using 100 and 150 kDa membranes. USN treatment increased the concentration of relatively low molecular weight SPS (4, 10 kDa) in the permeate (p < 0.05) but there was no significant (p > 0.05) effect on the high molecular weight SPS (300, 500 kDa). Membrane fouling was observed during the saccharides UF process, thus indicating that the process could be further improved.

Microalgae contain a diverse range of high-value compounds that can be utilized directly or fractionated to obtain components with even greater value-added potential. With the use of microalgae for food and medical purposes, there is a growing interest in their digestive properties and impact on human gut health. The extraction, separation, and purification of these components are key processes in the industrial application of microalgae. Innovative technologies used to extract and purify microalgal high-added-value compounds are key for their efficient utilization and evaluation. This review’s comprehensive literature review was performed to highlight the main high-added-value microalgal components. The technologies for obtaining bioactive compounds from microalgae are being developed rapidly, various innovative, efficient, green separation and purification technologies are emerging, thus helping in the scaling-up and subsequent commercialization of microalgae products. Finally, the digestive behavior of microalgae nutrients and their health effects on the human gut microbiota were discussed. Microalgal nutrients exhibit favorable digestive properties and certain components have been shown to benefit gut microbes. The reality that must be faced is that multiple processes are still required for microalgae raw materials to final usable products, involving energy, time consumption and loss of ingredients, which still face challenges.

This study aims at evaluating the impact of different processes-pulsed electric fields (PEF), pressurized liquid extraction (PLE) and a multistep process combining PEF + PLE on the yield of antioxidant compounds (protein, polyphenols, chlorophyll a, chlorophyll b, and carotenoids) from Spirulina. Firstly, the effects of PEF or PLE treatment on the extraction yield of Spirulina biomolecules were evaluated. To further increase the extraction yield, PEF + PLE was used, as an innovative extraction approach. The results showed that PEF + PLE greatly improved the extraction yield compared with the PEF or PLE treatments alone. Compared with Folch extraction (conventional control technique), PEF + PLE significantly (P < 0.05) shortened the extraction time (−165 min) and increased the protein, polyphenol, chlorophyll a and antioxidant capacity values of Spirulina extracts by 1328%, 979%, 11% and 47% respectively. Furthermore, Triple TOF-LC-MS-MS results showed that PEF + PLE increased both the type and content of phenolic compounds. The above results were attributed to PEF-induced damage on Spirulina helical structure, which was verified by fluorescence and scanning electron microscopy.

The aim of this work was to investigate the potential use of non-conventional technologies (microwaves, ultrasounds, pulsed electric fields, and high voltage electrical discharges) to enhance the extraction of high-added value compounds (mainly stevioside and rebaudioside A), and antioxidants (total phenolic compounds, flavonoids, chlorophylls, and carotenoids), from Stevia rebaudiana leaves. After treatment at equivalent energy, a supplementary diffusion was performed until 1 h. Results demonstrated that when water (100%) was used as solvent, the maximum recovery of stevioside (50.8 ± 0.1 mg/g) was obtained after ultrasound-assisted extraction, while microwave allowed the highest yields of rebaudioside A (22.7 ± 0.1 mg/g). However, pulsed electric field technology was the most efficient to recover stevioside (44.2 ± 0.1 mg/g) and rebaudioside A (22.4 ± 0.3 mg/g) when using 50% ethanol-water. Results obtained through this work pave the way toward the possible scaling-up of some of these non-conventional technologies for a multistep selective extraction of valuable compounds from Stevia leaves. Practical applications: Recovering high added value compounds (i.e. stevioside and rebaudioside A) from stevia leaves in food industry is usually performed using thermal extraction under agitation after drying and grinding. Although efficient, this technique generates an extract not only rich in targeted compounds but also in impurities, which complicates the downstream processing steps. Selective extraction of stevioside and rebaudioside A using non-conventional extraction technologies (i.e. pulsed electric field, etc.) may allow reducing the processing steps (grinding, downstream purification, etc.), and thus an alternative to the conventional method. For this reason, investigating the impact of these technologies at laboratory scale to recover target molecules from stevia leaves is of paramount importance before scaling up the process.

The main objective of this work was to nd new applications to valorize olive stones (endocarpand seed). In order to improve knowledge on olive stones, the phenolic compounds concentrationof three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied.Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy(FT-MIR). Total phenolic compounds are quanti ed a er solid-liquid extraction by an assay ofFolin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of totalphenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/gDM). ermogravimetric analysis indicates that up to 195°C; there is no degradation of the stones. e biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show thatthe most interesting results are obtained with Moroccan Picholine stones. e presence of MoroccanPicholine in a particleboard panels improves the total resistance of the particleboard panels againstboth Coriolus versicolor and Coniophora puteana rot fungi.

The main objective of this work was to nd new applications to valorize olive stones (endocarpand seed). In order to improve knowledge on olive stones, the phenolic compounds concentrationof three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied.Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy(FT-MIR). Total phenolic compounds are quanti ed a er solid-liquid extraction by an assay ofFolin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of totalphenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/gDM). ermogravimetric analysis indicates that up to 195°C; there is no degradation of the stones. e biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show thatthe most interesting results are obtained with Moroccan Picholine stones. e presence of MoroccanPicholine in a particleboard panels improves the total resistance of the particleboard panels againstboth Coriolus versicolor and Coniophora puteana rot fungi.

The main objective of this work was to nd new applications to valorize olive stones (endocarpand seed). In order to improve knowledge on olive stones, the phenolic compounds concentrationof three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied.Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy(FT-MIR). Total phenolic compounds are quanti ed a er solid-liquid extraction by an assay ofFolin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of totalphenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/gDM). ermogravimetric analysis indicates that up to 195°C; there is no degradation of the stones. e biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show thatthe most interesting results are obtained with Moroccan Picholine stones. e presence of MoroccanPicholine in a particleboard panels improves the total resistance of the particleboard panels againstboth Coriolus versicolor and Coniophora puteana rot fungi.

The main objective of this work was to nd new applications to valorize olive stones (endocarpand seed). In order to improve knowledge on olive stones, the phenolic compounds concentrationof three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied.Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy(FT-MIR). Total phenolic compounds are quanti ed a er solid-liquid extraction by an assay ofFolin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of totalphenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/gDM). ermogravimetric analysis indicates that up to 195°C; there is no degradation of the stones. e biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show thatthe most interesting results are obtained with Moroccan Picholine stones. e presence of MoroccanPicholine in a particleboard panels improves the total resistance of the particleboard panels againstboth Coriolus versicolor and Coniophora puteana rot fungi.